10 of the Most Dramatic Celebrity Hair Makeovers (PHOTOS)

Once upon a time, Miley Cyrus looked like every other really pretty teenage girl. She was wholesome and pure and had Disney Princess hair. But the singer and actress knew she had to change up her look big-time if she wanted to become an international success ...

... Miley's peroxide-blonde cropped 'do is too punk for Disney but perfect for her saucy new image.

Whether you love her or hate her, you have to admit Kim Kardashian makes one heck of a good brunette. Unfortunately, Kim became the poster girl for the phrase "Don't mess with a good thing" ...

... No, no, no. Putting blonde hair on Kim is like dressing up a good steak with ketchup. The color does little for her and just makes us pine for her dark locks.

This is what Jennifer Aniston usually looks like. She's pretty much perfect, wouldn't you say? And although it's true she is a natural brunette and has every right to go back to her roots, would you take a chance if you found a color this perfect for you??

We know Jen changed her look for her new role in the film Cake, but this photo proves the actress was born to be blonde and bronze and should change it back immediately.

Dancing With the Stars champ Julianne Hough once rocked super-pretty, but also super-common, beach blonde hair. Not one to easily blend into the crowd, she made one amazing change that got everyone talking ...

... Julianne isn't just another pretty face anymore -- she's a fashionable and spunky beauty style icon, and her edgy, angled pixie cut totally suits her fun personality.

Kate Middleton's hair rarely, if ever, looks anything less than stellar. No wonder we all get excited when the Duchess leaves the house with -- how shocking! -- a few gray hairs. Her long, side-swept, straight locks are glossy and easy to manage, but it was nice to see Kate shake things up just a bit ...

... Okay, maybe it wasn't the most drastic of hair changes, but for Kate, getting bangs was a good-hearted attempt to add some flair to her look. And, despite the fact that it didn't always work on windy days, we applaud the princess for trying to (sort of) break out of her beautiful mold.

Maggie Gyllenhaal's enormous blue eyes are intensified by her short and sweet brunette hair. She easily looks like a beauty from another era. But the actress's current look isn't doing her any favors ...

... Maggie's light blonde hair makes her look older and more washed out. She should leave this style to Miley and go back to her dark roots.

With her impossibly long and tousled bright blonde hair, Pamela Anderson has always been the epitome of the California surfer babe. While the look helped catapult the Baywatch babe to fame in her 20s, it started looking a little dated and boring as she matured ...

... Surprise! Pamela shocked us all by chopping her mane into an extremely chic pixie cut that makes her look every inch the French ingenue.

Anne Hathaway + long hair = gorgeous and glam. But lots of girls in Hollywood have long, layered styles. The actress showed the world she has courage and edge by drastically changing up her look ...

... Anne's sleek and sophisticated haircut opens up the doors for the actress to take on more grownup and serious roles.

Leah Messer of Teen Mom 2 fame once looked like your typical small-town girl. What a difference a few years and a good stylist can make ...

... Wow! Leah straightened and colored her hair a darker shade of blonde, and the result is a much more glam and urban-cool look that really works on her.

Demi Lovato used to sport a gorgeous mane of long, dark hair that made her look a lot like Snow White ...

... I get it, Demi. You're young and sassy and want to show the world you've come a long way from the days when you were dancing on TV with Barney. And I do feel like your mom for saying this, but you are such a pretty girl. Please grow your hair back.